Re: [PATCH v2 10/16] selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr

[Vincenzo Frascino <vincenzo.frascino@arm.com>]

On 26/02/2025 11:44, Thomas Weißschuh wrote:
> vdso_standalone_test_x86 is the only user of vdso_init_from_auxv().
> Instead of combining the parsing the aux vector with the parsing of the
> vDSO, split them apart into getauxval() and the regular
> vdso_init_from_sysinfo_ehdr().
> 
> The implementation of getauxval() is taken from
> tools/include/nolibc/stdlib.h.
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> 

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
> All of this code will be deleted later again.
> ---
>  .../selftests/vDSO/vdso_standalone_test_x86.c      | 27 +++++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
> index 644915862af8883131e5defd336f1bd80736fc0f..500608f89c66b5747e3d845ebc54e4c3a35b6ccd 100644
> --- a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
> +++ b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
> @@ -15,6 +15,7 @@
>  #include <sys/time.h>
>  #include <unistd.h>
>  #include <stdint.h>
> +#include <linux/auxvec.h>
>  
>  #include "parse_vdso.h"
>  
> @@ -84,6 +85,30 @@ void to_base10(char *lastdig, time_t n)
>  	}
>  }
>  
> +unsigned long getauxval(const unsigned long *auxv, unsigned long type)
> +{
> +	unsigned long ret;
> +
> +	if (!auxv)
> +		return 0;
> +
> +	while (1) {
> +		if (!auxv[0] && !auxv[1]) {
> +			ret = 0;
> +			break;
> +		}
> +
> +		if (auxv[0] == type) {
> +			ret = auxv[1];
> +			break;
> +		}
> +
> +		auxv += 2;
> +	}
> +
> +	return ret;
> +}
> +
>  void c_main(void **stack)
>  {
>  	/* Parse the stack */
> @@ -96,7 +121,7 @@ void c_main(void **stack)
>  	stack++;
>  
>  	/* Now we're pointing at auxv.  Initialize the vDSO parser. */
> -	vdso_init_from_auxv((void *)stack);
> +	vdso_init_from_sysinfo_ehdr(getauxval((unsigned long *)stack, AT_SYSINFO_EHDR));
>  
>  	/* Find gettimeofday. */
>  	typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);
> 

-- 
Regards,
Vincenzo